Blind-stitch sewing-machine.



. No. 705,325. Patented July- 22, |902. f l c. A. DEARBURN.-

BLmnsmcH SEWING MACHINE.

(Arpplication filed Nov. 26, 1900.) (No Model.) 3 Shees-Shqet 2.--

.ff QW No. 705,325. Patente-d July 22, |902. C. A. vDEABBORN.

-` BLINDSTITCH SEWING MACHINE.

(Application led Nov. 2k6, 1900.)

(N u Model.) f' Y 3 Sheets-Sheet 3,

m LOM.

UNITED STATES PATENTl OFFICE.

CHARLES A. DEARBORN, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS,TO FREDERICK \V.LORCH.

BLIND-STITCH SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent 310.705,325,A datedhuly 22,1902.

Original application filed March 2l, 1900, Serial No. 9,500. Divided andthis application filed November 26, 1900. Serial No. 37,745. (No model.)

To all whom t may' con/cern:

Be it known that LCHARLES ADEARBORN, a citizen of the United States,residing at New York, in the county and State of New York, have inventedcertain new and useful Improvements in Blind-Stitch Sewing-Machines, ofwhich the following is a specification.

My present invention relates to improvements in stitch-forming mechanismfor sewing-machines, which are particularly applicable to the style ofsewing-machines for blindstitching set forth in Letters Patent No.639,669, granted to me December 19, 1899, and my present application isa division of my original application,Serial No.9,500,which was filed inthe Patent Office March 21, 1900.

In practically developing the machine covered by my above-named patentIencountered several difficulties more or less serious to the properoperation of vthe machine, and my present improvements have been devisedfor the purpose of overcoming` these difficulties. The machine of mysaid patent embodies a suitable feed mechanism, a rigid presser-foot, aneedle reciprocating transversely to the path of the work, and a loopercooperating with the needle and provided with suitable operatingmechanism to cause it to first move forwardly at one side of the line ofstitching' to take a loop from the needle above the work,

then axially to carry the looper across the` line of stitching, thenrearwardly above the work to enable the looper to present the loop tothe needle, and finally a second axial or rocking movement to carry thelooper back across the line of stitching to its first position. The feedmechanism of this patented machine comprises, essentially, a rotarycylindex' having two serrated portions and a ridge-forming rib betweenthe serrated portions and means for giving the feed-cylinder anintermittent rotary motion. mechanism isvmounted upon a spring-sustainedframe, .the spring of which holds the feed-cylinder into workingrelation with the work under the stationary presser-foot, forms a ridgein the work for the penetration of the needle, and allows the feedmechanism to yield sufliciently to acgommodate the thickness of thematerial being operated upon.

The feedl Some of the features of my above-named originalapplioation,Serial No.9,500,(of which my present application is adivision,) are illustrated and described in a general way in my presentdivisional application, but they do vnot form an essential part of mypresent invention and are set forth only for the purpose of giving aproper understanding of the machine in connection with which my presentimprovements are explained. The looper in said patented machine'isjournaled in a pivotally-mounted sleeve or bearing, so as to slidelongitudinally and oscillate therein andl have a vertical rocking motionupon the pivot of the bearing-sleeve during its forward and backwardmovements under the action of its operating crank mechanism. This is nota satisfactory,construction for commercial machines, the principalobjection to it being that the looper hastoo great avertical throw whenit is in its forward position. In the machine of my present applicationI have avoided this objectionable feature of lthe looper stitchformingmechanism by arrangingaswinging bearing for the looper-rod. A rock-armis journaled upon the machine-frame, so as to be capable of movementtoward and away from the path of the needle, the looper-rod havinguniversal-joint connection with the free end of the rock-arm. In thisconstruction the looper is at a fixed distance in front of its swingingbearing at all of its positions, and the movements ofthe bearing towardand away from the path of the needle assist in causingthe Vlooper torise and fall during its axial movements to properly coperate with theneedle and without interfering with the presser-foot, the work, or thefeed m echanism.

In the machine of my present application I provide a needle-guidewhichis capable of moving into and out. of operative vrelation to theneedle, so as to hold the needlerigidin its path until it has enteredthe work, when the guide recedes to get out of the way of theneedle-supportingarm. Bythisarrangement of the needle-guide it ispossible to use a relatively short and rigid needle, which is preferabletoa long needle, which would have to be used if a stationaryneedle-guide were employed for directing theneedle into the work.

IOO

Another important feature of my present application is the combination,with the needle and looper, of an upper feed device which engages theupper exposed face of the work and travels with it, and by theengagement of the lower thread of the loop (carried over the work by thelooper) with its smooth properly-shaped face elfects the placing of saidlower thread of the loop suliciently far in advance of the path of theneedle to insure the penetration of the loop by the needle just prior tothe penetration of the workin the formation of a stitch. The movement ofthe work under the action of the ordinary feed tends to move said lowerthread of the loop into proper position for the needle to take the loop;but I have found in practice that any slight uneven places upon thegoods will cause said lower thread of the loop to be retarded when drawnover the work by the looper, resulting in the dropping of a stitch. Thepresence of this upper feed-finger affords a smooth surface over whichthe said under thread of the loop slides into proper position under theaction of the looper.

In order that my invention may be fully understood, I will firstdescribe the saine with reference to the accompanying drawings andafterward point out the novelty more particu- -larly in the annexedclaims.

In said drawings, Figure 1 is a plan view of a sewing-machine embodyingmy improvements. Fig. 2 is a side elevation of the same looking at thestitch-forming mechanism, which is at the left-hand side of the machine.Figs. 3 and 4 are detail views illustrating the swinging bearing of thelooper-rod. Figs. 5 and 6 are detail sectional plan views illustratingmy improved stitch-forming mechanism. Fig. 7 is a detail side elevationof my improved needle-guide, representing it withdrawn from the path ofthe needle-carrying arm.

The machine is built upon a base of any suitable construction, such asis shown..

1 indicates the rigid central base-frame, having an upwardly-extendingrear arm or section 2, terminating in the sleeves or shaftbearings 3 and4, and the forwardly-extending arm 5, having journal-bearings 6 and 7and supporting upon alug Sthe rigid presserfoot 9. The base-frame alsohas a central vertically-extending broad portion 10, terminating in asleeve 11.

15 is the main driving-shaft of the machine, journaled in the sleeves orbearings 3 4 of the base-frame and having keyed to one end adriving-pulley 16 and iiy-wheel 17 and at its opposite end a crank-disk1S. Projecting at an angle of forty-five degrees from the crankdisk 18is an arm 19, supporting a crank-pin 20, upon which is swiveled thesleeve 21, which is capable of rotating thereon.

22 is a yoke pivotally connected with the sleeve 2l and adj ustably andrigidly secured to the rear end of the looper-rod 25. This part of themachine is more fully illustrated in my above-named Patent No. 639,669.

30 is a suspended rock-arm journaled at its upper end upon a pin 31,which is eccentrically secured in a block 32, which is adjustablymounted in a suitable socket 33 of the sewing-machine arm 5. The block32 is formed with a wrench-head 34, by means of which it can be rotatedin its support for adjusting the pivot-pin 3l upwardly or downwardlyvwith relation to the plane of feed of the work.

35 is a set-screw threaded into a suitable opening in the sewing-machinearm 5 and adapted to engage the adjustable block 32 for securing it inthe desired adjusted position. The rock-arm is suspended from a pointabove the horizontal plane of the looper-rod.

The lower free end of the rock-arm 30 is formed with a removablebearing-yoke 36, secured to the arm by screws 37, the inner surfaces ofsaid yoke 36 and the corresponding face ot' arm 30 being cut out to forma circular concave bearing or socket. The looperrod 25 has secured to ita spherical bearinghead 38, which rests in the concave bearing or socketformed at the free end of the rockarm 30, so as to cause the rock-arm 30to move forwardly and backwardly upon its bearing 31 under the action ofthe longitudinal movemeutof the looper-rod 25 and at the same time allowmovement between the looper-rod and rock-arm in all directions. Thebearing connecting the looper-rod to the rock-arm is, in effect, auniversal-joint connection. The floating bearing carried by the rock-arm30 is raised and lowered as the looper-rod moves forwardly andbackwardly.

Atthe forward end of the looper-rod 25 is mounted the looper proper, 40,having two tingers or prongs 40 and 40h and a bent stem 40C, connectingit to the looper-rod 25. The specific construction of the looper properis the same as described and illustrated in my above-named patent. Byadjusting block 32 the looper 40 can be moved upwardly or downwardlywith relation to the path of the needle to insure the passage of theneedle centrally between the prongs of the looper and also thenon-interference of the looper with the rest of the mechanism.

45 is the needle rock-shaft, journaled in the machine-frame bearings 6and 7 and having rigidly mounted upon its forward end a needle-carryingrock-arm 46, in which is mounted the curved needle 47.

48 and 49 are ordinary thread-guides. Secured to the rear end of theneedle rockshaft 45 is a rock-arm 50, having universaljoint connection51 with a link 52, which encircles an eccentric 53, mounted upon themain power-shaft 15 adjacent to the crankdisk 18. The link 52 and theeccentric 53 are formed with mated spheroidal engaging surfaces to allowfree lateral play of the link. By means of the mechanism just describedIOO IXO

the needle is given a reciprocatorymotion in an arc transverse to thepath of the work which is fed by the mechanism presently to bedescribed.

The rigid presser-foot 9, which, as above stated, is supported from thelug 8 of the machine-frame arm 5, is formed with a central longitudinalgroove 9FL in its under face and two approximately-parallel elongatedopenings 9b and 9C, arranged upon opposite sides of the central groove.

55 is a spring-tongue rigidly secured to a lug 9d of the presser-footand extending under another similar lug 9e. This spring-tongue 55 iscapable of yielding but slightly, it being confined in its spring actionby the lugs 9d and 9e.

The structure of the rigid presser-foot 9 and spring-tongue 55, mountedthereon, do not form any part of the inventionclaimed in my presentcase, and I have therefore not attempted to fully illustrate thesefeatures. A more complete understanding of these features may be had byreferring to my abovenamed original application, Serial No. 9,500, or toBritish Patent No. 19,556 of 1900, granted to me for the same invention.

In order to permit the use of a short needle in my machine and obviatethe necessity of using the objectionable long needle, I provide aneedle-guide which normally engages the needle to insure its properengagement with the work and which intermittently moves away from thepath of the needle to avoid interference with the needle-supporting arm.

is a short rock-arm jou rnaled to the sewing-machine arm 5 at 60H, and62 is the shank of the needle-guide 63, which is vertically adjustablein the rock-arm G0 and secured in any desired position therein by meansof a set-screw 64. The rock-arm 60 has a rearwardly-extending heel 6l,which is engaged by a cam 65, keyed to the needle rock-shaft 45. Aspiralspring 66 surrounds the journal 61 and engages at its opposite ends therockarm 60 and machine-arm 5, giving the needle-guide a spring tendencyto move away from the needle and out of the path of the needle. Theaction of the cam 65 upon the heel of the rock-arm 60 intermittentlymoves the needle-guide into operative relation to the needle.

Journaled in the bearing 1l upon the central upwardly-projecting arm 10of the machine-frame is the forwardly-extending main feed-frame 70.

75 is the main feed-shaft, journaled in the pivot feed-frame andcarrying at its outer end a cloth-supporting ridge-forming disk 76 and aserrated main feed Wheel or roll 77. The disk 76 and feed-wheel 77 arerigidly secured upon the shaft by` means of a suitable collar 78 andscrew-nut 79. The disk 76 has a slightly greaterdiameter than thefeedwheel 77, so as to project circumferentiallya little beyond thefeed-wheel 77 and form a rib or ridge in the work by pressing it up intothe opening of the rigid presser-foot. The size of the ridge-formingdisk 76 with relation to the size of feed-wheel 77 will in practice bevaried to suit differentthicknesses of work to be sewed. Keyed to theopposite end of the feed-shaft 75 is a clutch-wheel 80, with whichengage the frictional feed-dogs 8l, mounted upon au oscillatory frame82, which has a rocking motion imparted toit by any suitable mechanismto cause the intermittent rotation of the ridge-forming disk 76 andfeedwheel 77.

The feed wheel or roll 77, just described, lconstitutes one of theyieldingly-.supported lower feed members of my machine. The otheryieldingly-supported lower feed member (not shown) is mounted uponauxiliary feed-shaft 92, which is journaled in auxiliary frame 95 and isdriven by an internal gear 90, keyed to shaft 75. The auxiliary lowerfeed member rests alongside the ridge-forming rib 76 under thepresser-foot. The structure of this divided under feed is fullydescribed and illustrated in my above-named original application, SerialNo. 9,500, and I will not describe the same in detail in my presentcase.

The main feed-frame 70 is formed with a downwardly-projecting arm 70,which engages a limiting screw or stop 70h, mounted in the part 10 ofthe machine-frame.

70c is a spiral spring engaging a lug 70d on the arm 70zt and having itsopposite end attached to an adjustable curved arm 105, mounted in thepart 10 of the machine-frame. The purpose of the spring just describedis to yieldingly support the feed-frame 70 normally in raised positionand at the same time allow said frame to be depressed for the insertionof the Work beneath the presser-foot and also to allow the frame toyield sufficiently for the thickness of the material which is passingthrough the machine.

106 is a forwardly-projecting handle by which the feed-frame can bedepressed for the insertion of the work between the rigid presser-footand lower feed mechanism.

In addition to the two-part under feeding mechanism to which I have justreferred I provide an upper feed device which is adapted to engage theupper exposed face of the work within the opening of the rigidpresserfoot. This upper feed device comprises a feed-finger proper, 110,having a serrated or pointed engaging end and a smooth curved upperface, and it is formed upon a curved supporting-shank 111. Adjustablyattached to the feed-finger 110 and extending under it in the directionof feed of the work is an auxiliary spring-finger 112, formed with atransverse needle guide or gate 112l and adapted to engage the Workadjacent to the path of IOO IIO

the needle and above the ridge-forming ribI of the disk 76, the needlepassing through said guide or gate 1122L into the material.

113 is a set-screw adj ustably securing said spring-finger 112 to thefeed-nger 110.

The feed-linger 110 and spring-finger 112 serve two important purposes.In the first place, the spring-finger 112 confines the ridge of the workabove the ridge-forming rib and insures a uniform penetration of thematerial by the needle, a function which I have found practicallynecessary in producing uniform blindstitching. In the second place, thefeed-linger 110 and spring-finger 112 moving with the work up to themoment of penetration of the work by the needle effects The placing ofthe lower thread of the loop (on the looper) sufficiently far in advanceof the path of the needle to insure the penetration of the loop by theneedle just prior to the penetration of the work. The movement of thework under the action of the feed tends to move said lower thread of theloop into proper position for the needle to take the loop; but I havefound in practice that any slight uneven places upon the goods willcause the said lower thread of the loop to be retarded when drawn overthe work by the looper, and the presence of the said feedlinger 110aords a smooth surface for the said under thread of the loop to be drawnover into proper position bythe action of the looper.

The shank 111 of the upper feed-finger is adjustably mounted in a socketformed in the forward end of a rock-arm 114, which is rigidly secured toa rock-shaft 115, journaled to the upper free end of the approximatelyvertical rocking frame 85.. A link rock-arm 116 is rigidly secured tothe rockshaft 115 and extends rearwardly to the main driving-shaft 15 ofthe machine and terminates in a yoke 117,which encirclesan eccentricupon shaft 15.

The operation of the machine will be clear with but slight furtherexplanation. The

machine is primarily intended to accomplish overseaming-blindstitching,which is useful in seaming the lower edges of trousers-legs, skirts, andother garments. The material to be sewed is folded at one edge to formthe hem of the desired depth and by depressing the feed-frame isinserted in the machine between the under feed devices and presserfoot,the turned-up portion or hem of the material (the double thickness)being placed to the right just over the auxiliary feed device. When thefeed-frame is released, it returns to its normal raised position andforces the main and auxiliary under feed devices and the ridge-formingdisk or plate up into engagement with the work, said ridge-forming disk76 pressing a ridge or rib of the work up into one of the openings ofthe presser-foot alongside of the spring-tongue 55, which latter holdsthe material to the action of the main under feed-wheel 77. The upperfeedfinger 110 (on its forward stroke) and springfinger 112 engage thework over the ridgeforming rib 7G, and the inner edge of the rigidpresser-foot forces the work down into engagement with the auxiliaryunder feedroll, thereby forming an 'abrupt edge of the rib or ridge inthe work to cause the needle to emerge from the work just above the thininner edge of the 4presser-foot. At the moment the needle starts topenetrate the rib or ridge in the work the feed devices are at rest. Theneedle penetrates lthe ridge of the work transversely of the directionof feed and moves to the right until its point is a sufficient distancefrom the work-ridge to form a loop of the needle-thread sufficientlylarge for the looper to take. Just as the needle starts to return(forming on the upper side of the needle an arc or loop X in the threadfrom the needle-eye to the work-ridge, as usual) the looper is on itsforward stroke, with its two prongs or 'fingers in the same horizontalplane, the two prongs or fingers of the looper passing into engagementwith and taking the loop and moving axially with it to carry it to theneedle side of the workridge as the needle completesits return movement.When the needle has completed its return movement and is about to startforward on another stroke, the looper is beginning its backward stroke,with both of its prongs or lingers in the same vertical plane holdingthe thread-loop open for the entrance of the needle. Just as the needleis about to enter the thread-loop the lower thread of the loop comesinto contact with the upper smooth curved face of the upper feedfinger110 and slides forwardly thereon to get in front of the needle to insurethe needle taking the loop. The needle then passes through thethread-loop into the guide or gate 112a of spring-finger 112 andpenetrates the work-ridge above the disk 76, the finger 112 holding theridge of work firmly down upon the disk to insure the penetration of theneedle at the proper depth to make a blind stitch. The needle-guide 63is in position to guide the needle during the greater part of itsstroke, receding just in time to get out of the way of theneedle-supporting arm on the forward stroke of the needle after theneedle has penetrated the work and coming back into operative positionon the return stroke of the needle just after the needlesupporting armhas moved back out of its way and before the needle has been entirelywithdrawn from the work.

The upper feed-finger has a forward movementin an approximately straightline, then an upward and rearward movement above the work, and adownward movementinto engagement with the work for another forwardfeeding stroke, the movements of the upper feeding-finger describing anellipse fiattened on its lower side.

Having thus described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is-

1. In a sewing-machine, the combination of a reciprocatory needle,suitable feed mechanism, and means for operating the needle and feed,with a looper-rod carrying a looper which coperates with the needle,means for impartinga longitudinal reciprocatory move- IIO ment and anaxial oscillatory movement to said looper-rod, a suspended rock-armsupported at a point above the horizontal plane of the looper-rod andcapable of swinging toward and away from the path of the needle underthe action of the looper-rod, and a universal-joint bearing connectingthe looperf rod with the lower end of said rock-arm, substantially asset forth.

2. In a sewing-machine, the combination of a reciprocatory needle,suitable feed mech-, anism, and means for operating. theneedle and feed,with a looper-rod carrying a looper which coperates with the'needle,means for imparting a longitudinal reciprocatory move-4 ment and anaxial oscillatory movement to said looper-rod, a rock-arm'journaled uponthe machine-frame and capable of swinging toward and away from the pathof the needle, means for adjusting the journal of said rock-arm, and auniversal-joint bearing connecting the looper-rod with said rock-arm,substantially as set forth.

3. In a sewing-machine, the combination of suitable feed mechanism, areciprocatory needle arranged to reciprocate transversely to the line offeed, and means for operating the needle and feed, with a looperrodarranged with its longitudinal axis approximately parallel with the lineof feed, a looper carried by the looperrod and adapted to coperate withthe needle, means for imparting a longitudinal movement and an axialoscillatory movement to said looperrod, a rock-arm suspended from apoint above the horizontal plane of the looper-rod and capable ofswinging toward and away from the path of the needle underthe action ofthe looper-rod, and a universal -joint bearing connecting the looper-rodvwith the lower end of said rock-arm, substantially as set forth.

4. In a sewingamachine, the combination of suitable feed mechanism, aneedle arranged to reciprocate transversely to the line of feed, andmeans for operating the needle and feed, with a looper-rod carrying atits forward end a looper which coperates with said needle, an eccentricrotating device lhaving adoublejoint connection with the rear end ofsaid looper-rod for operating it, a rock-arm suspended from a pointabove the horizontal plane of the looper-rod and capable of swingingtoward and away from the lpath of the needle under the action of thelooper-rod,

anda universal-joint bearing connecting the looper-rod with the lowerend of said rockarm, substantially as set forth.

5. In a sewing-machine, the combination of suitable feed mechanism, withsuitable stitchforming mechanism including a needle rockshaft, means foroperating the rock-shaft, a

vrock-arm upon said rock-shaft, a needle mounted upon said rockarm, anoscillatory needle-guide, and means operated by the needle rock-shaftfor moving the needle-guide into and out of operative relation with theneedle, substantially as set forth.

6. In a sewing-machine, the combination of suitable work-feedingmechanism, a needle,

exposed surface adjacent to the path of the needle and having aloop-guiding upper sur-4 face over which the lower thread of the loopupon the looper slides to a position in front of the path of the needle,thereby insuring the passage of the needle through the loop,substantially as set forth.

' CHARLES A.. DEARBORN. Witnesses:

WM. E. KNIGHT, J. GREEN.

